1. Field of the Invention
The present invention relates to a method of fabricating contact structures, and more particularly to a method of fabricating self-aligned contact structures in semiconductor devices.
2. Description of the Prior Art
In multilayer integrated circuit processing, a cover layer on the semiconductor substrate is usually etched by a vertical hole to form a conductive contact on the substrate. Several layers formed of different materials need to be etched. In order to ensure that the conductive contact only conducts with the semiconductor substrate, other structures, such as transistor gate structures, are isolated by an isolation sidewall and the cover layer.
However, this isolation structure is a limitation in the semiconductor device with multilayer metal interconnects during lithography processing.
As a result, the present invention provides a method of fabricating self-aligned contact structures to improve the disadvantages above.